1. Technical Field
Various embodiments of the inventive concept relate to a variable resistance memory apparatus, more particularly, to a variable resistance memory apparatus having a multi-level cell, and a manufacturing method thereof.
2. Related Art
In recent years, with demands on semiconductor memory apparatuses with high performance and low power, next generation semiconductor memory apparatuses with non-volatility and non-refresh have been researched. As one of the next generation semiconductor memory apparatuses, variable resistance memory apparatuses are suggested, and typical examples of the variable resistance memory apparatuses are phase-change random access memory apparatuses (PCRAMs), resistive RAMs (ReRAMs), magnetic RAMs (MRAMs), spin-transfer torque magnetoresistive RAMs (STTMRAMs), or polymer RAMs (PoRAMs).
A cell pitch or an area occupying by one cell is reduced to accomplish high integration in recent variable resistance memory apparatuses.
However, the process of reducing the cell pitch or the cell area to accomplish the high integration may be difficult, and electrical characteristics or reliability of the variable resistance memory apparatus are degraded due to a void formed in a data storage unit during the process.
Therefore, it may be necessary to introduce a multi-level cell that may store multi-bits in one memory cell, to implement a variable resistance memory apparatus with high integration and large capacity.